I was attacked by a dog as a child, so I'm not really a fan. I do not say hello to them. I've had people say, "You're not really a dog person, are you?" and I acknowledge that and appreciate that they are okay with me being standoffish. I'm not usually afraid of them, although I can't stand German shepards since the attack, I just don't like being near them.
I hear you. I am the same way with white dogs and small dogs (below my knee) as every attack (and there have been many) has been by these dogs. So I am overly cautious about dogs, and if I walk in to a house and a dog jumps on me, I will turn around and head out until they control them.